Electric-current rectifier



S.l RUBEN ELECTRIC CURRENT RECTIFIER March 18, 19.30.

Original Filed Aug. 20. 1925 Se Te IN VEN TOR.

v MM A TTORNEYS.

M9 or amalgam yPatented Man 18, 1930 UNITED STATES PATENT OFFICE SAMUELRUBEN, OF NEW YORK, N. Y., ASSIGNOR '10 RUBEN RECTIFIER CORPORATION, OFENGLEWOOD, NEW JERSEY, A CORPORATION OF DELAWARE ELECTRIC-CURRENTRECTIFIER Original application filed August 20,

This invention relates to asymmetric electric couples and moreparticularly to electric couples adapted to be used in alternatingcurrent rectifying devices and the like, which are of the dry surfacecontact variety. n

Rectiers of this type are characterized by the use of a body ofelectropositive material, employed as one electrode element .disposed inelectrical contact with a body of electronegative material employed as'the other electrode elements. Such rectifiers depend for theiroperationvupon the resistance and current blocking characteristics ofthe lm which forms at the junction ofthe electrode element as the resultlofelectrochemical, action. Rectiers of this character, knownV to theprior art, have been low in efiiciency and limited in their applicationto small currents, becoming unstable after short periods of use.

The present invention accordingly has for its object, generally, toprovide a device of the character specified which is eilicient,economical and readily manufactured. Specifically its of electrodeelements in electric couples which is free from high internal resistanceand low output voltage and which are'adapted for film formation andmaintenance and do not require aging or other electrical or chemicaloperating development to insure unilateral conductivity.

This application is a -continuation in part of my prior co-pendingapplications, Serial No. 739,188, filed September 22nd, 1924, now PatentNo. 1,649,741; Serial No. 750,539, filed November 18th 1924, now lPatentNo. 1,649,- 7 42; Serial No. 754,956, filed December 10th, 1924; SerialNo. 155, led January 2nd, 1925, now Patent No. 1,649,743; Serial No.13,143, filed March 5th, 1925, now Patent No. 1,649,- 744; Serial No.14,657, iiled March 11th, 1925; and Serial No. 38 780, filed June 22nd,1925, now Patent No. 1,723,525 and is a `division of my applicationSerial No. 51,524, filed August 20th, 1925. y

Other objects of the invention will in part be obvious and will in partappear hereinafter. Y 5 For a fuller understanding of the nature objectis to provide an arrangement 1925, Serial No, 51,524. Divided and thisapplication nl ed December 20, 1929. Serial No. 415,411.

and objects of the invention, reference should be had to the followingdetailed 'description taken in connection withthe accompanying drawing,in which:

Fig 2 shows schematically a dry surface' :contact electric coupleconstructed in accordance with the invention.

Referring now to the drawing, and particularly to Flg. 2, 10 denotes anelectropositive" electrode element-in disk form which may be made of -arelativelyhighly electropositive 1=metal','for example, magnesium. Theelectronegative electrode element is also ofl a disk-like orwasher-shaped form, and is shown at 11 in direct contact withtheelectropositive element.

In the practice of the invention, the electronegative element hereprovided is a metallic compound with at least one of the elements of thesixth periodic group, chosen from what is commonly known as the oxygenfamily. While those elements thereof which are conductive, as, forexample,I tellurium or selenium, may be used in their normal st ate,

lstill those elements from this family which are non-conductive, suchas, for example, oxygen and sulphur, may be readily used when incombination with a metal forming a conductive compound, such as, forexample, the metallic oxides, sulphides, tellurides and selenides. Thesesubstances give asymmetrical electrical conductive effects when coupledwith a relatively electropositive chemical element or compound, such asmetallic magnesium or its amalgam and the greater the divergence in theelectrochemical scale between the substances used for theelectropositive and the electronegative electrode elements, the moreeffective the rectification.

It has also been discovered that current rectification requires contactpotential diierence, and that if the initial or inherent contactpotential is insuiiicient, as in the case of a couple composed ofaluminum and cupric sulphide in contact, the desired contact potentialdiference may be attained by the interposition of a resistance betweenthe elements,

as for example, by the oxidation of one of the elements.

A sulpliided copper alloy lends itself readily to such use and may beconsidered as a somewhat icxible element capable of resistance in theelectrostatic forces by its movement in synchronisin with the electriciield.

Such an alloy compound improves the physical characteristics of thecouple, particularly by minimizing oxidation or decomposition rentblocking film attlie junction with` the' electropositiveelectrodeelement without the use of an interposed resistance layer; Bythese properties, forming currents custom` arily employed in theso-.called aging processes may be dispensed with.y

An electronegative electrode of the employing a sulphided coppercompound which is derived by the use of'an alloy. Al

practicable method of providing such a sub,- stance will be found to bethat of employing a copper alloy in which the alloy material has aninherently higher resistance than pure cupric sulphide, and thereafterheating the* metal to approximately 800 C. in the presence of sulphur,and finally permitting the mass to cool'.- Thus, a copper compound isproduced, the' body of which has a higher specific resistance than thatof. pure cupric sulphide, and such a body will not require the use of afacing or intermediate oxide layer when utilized for electricalrectification purposes. y

Vhile other alloys may be employed, it is particularly desirable to formthe electronegative electrode element from a copper compound, it being`aperferable element and readily forming the desired compounds, such assulphide, selenide, telluride and oxides. The material added to vary itsiinal re sistance could be lead, tin, zinc, antimony, or any other thatwill itself form a. sulphide or compound having a greater electricalresistance than the copper sulphide.

An assemblage of couples retained under suitable pressure is shown inFig.-1, where 12 denotes a bolt which is passed through a plurality ofaligned asymmetric couples 13 that are arranged in series in two groupsinverted with respect to each other; the bolt 12 is insulated from thesecouples by means of a sleeve of insulation shown at 14. Interposedbetween the inverted groups of asymmetric couples is a common electrode15. This electrode is preferably disposed in contact with theelectronegative electrode element of each group so that Athis electrodeserves as a nega- 1,751,aes n tive terminal, as indicated, for thecircuit traversed by the rectified current.

Substantially midway of the series of asyma positive terminal, but, forsimplicity of illustration, the circuit comprising the conductors20,'21jand 22 is shown as connected to but one positive terminal so asto be traversed by only one-half of the alternating current'wavereceive'dby'the rectifying device. Inseries with the conductors 21 and22 which connect With the positive terminal of the rectifying :deviceshown in service, is connected acutcli-ar-` acter indicated abovelmay bepro'ducedby out vdeviceshown generally at 23. This cut- .'olutdevice maybe of any convenient type, but ispreferably-.one having unilateralconductivity and'may be an asylmmetric couple of Lthesametype asused int itself@ Y' e rectifying device I I't-will be found that an electricalrectifier lconstructed,'finaccordance with the present inventionprovidesfpracticable units of hi h capacity, and its capacity is notlimited by leakage or incompletely formed areas. When assembled theunits require no formation process andare immediately on assemblycommercially operable, in addition to the fact that the rectifier may belutilized in connection with low power transformers, for the reason thatit does not re uire the intense lformation current, or the re ormationof any area due to hydrolytic or other secondary reactions. Also, theunits are especially adapted for instantaneous or intermittent use,especially the latter, so that a device embodying the subject matter ofthe present invention can be employed to supplant storage batteries forsuch uses as signal circuits. Due to the initial rectificationcondition, and no formation current being necessary, it is nowpracticable to utilize a rectifier of this type in numerous novelassociations, and because of its inherent asymmetrical conductivecondition the discharge of a battery upon the interruption of thecharging current is cut to a negligible minimum. Furthermore, wherecupric compound disks are employed it will be found that these elementswill resist breakage stresses, and even though relatively thin, they mayreadily be ground to have a hard, smooth surface, so that uniformity ofproduction may be assured, and the rectifier will not polarize byelectrochemical reaction.

It will also be understood that the following claims are intended tocover all of the generic and specific features of the invention iooherein described and all statements of the scope of the invention whichas a matter of language might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secureby Letters Patent, is:

1. In dry surface contact rectiying devices and the like, an asymmetriccouple comprising an electropositive electrode elementof magnesium, andan electronegative electrode element formed of electronegative materialcontaining a maximum valent compound of copper with a chemical elementfrom the sixth periodic roup beginning with the letter S where y saidelectronegative electrode element has inherently reactlon propertiesadapted for the formation and maintenance of an inverse current blockingfilm at the junction of said electrode elements; said couple havingmeans for maintaining the elements thereof united under pressure.

2. In dry surface contact rectifying devices and the like, an asymmetriccouple com- A prising an electropositive electrode element ofmagnesium,I and an electronegative electrode element formed of cupricsulphide whereb said electronegative electrode element W en subject tonormal volta e has reaction properties adapted for the ormation andmaintenance of an inverse current-blocking film at the junction of saidelectrode elements; said couple having means for maintaining theelements thereof united under pressure.

3. In dry surface contact rectiying devices and the like, an asymmetriccouple comprising an electropositive electrode element of magnesium, andan electronegative electrode element formed of electronegative materialcontaining a compound of copper with the chemical element sulphur in anamount whereby said electronegative electrode element when subject tonormal voltage has reaction properties adapted for the formation andmaintenance of an inverse current-blocking film at the junction of saidelectrode elements; said couple having means for malntaining theelements thereof united under pressure.

In testimony whereof I aiiix my si ature.

SAMUEL R EN.

